package com.skyworth.web.wechat.common;

import java.security.MessageDigest;

/**
 * Created by yuhaichao on 2016/8/23.
 */
public class MD5Encode {
    private final static String[] hexDigits = {"0", "1", "2", "3", "4", "5", "6", "7",
        "8", "9", "a", "b", "c", "d", "e", "f"};

/**
 * 转换字节数组为16进制字串
 * @param b 字节数组
 * @return 16进制字串
 */
public static String byteArrayToHexString(byte[] b) {
    StringBuilder resultSb = new StringBuilder();
    for (byte aB : b) {
        resultSb.append(byteToHexString(aB));
    }
    return resultSb.toString();
}

/**
 * 转换byte到16进制
 * @param b 要转换的byte
 * @return 16进制格式
 */
private static String byteToHexString(byte b) {
    int n = b;
    if (n < 0) {
        n = 256 + n;
    }
    int d1 = n / 16;
    int d2 = n % 16;
    return hexDigits[d1] + hexDigits[d2];
}

/**
 * MD5编码
 * @param origin 原始字符串
 * @return 经过MD5加密之后的结果
 */
public static String encode(String origin) {
    String resultString = null;
    try {
        resultString = origin;
        MessageDigest md = MessageDigest.getInstance("MD5");
        md.update(resultString.getBytes("UTF-8"));
        resultString = byteArrayToHexString(md.digest());
    } catch (Exception e) {
        e.printStackTrace();
    }
    return resultString;
}

}
